Shell : How to append text to a file with ease

Shell Scripting @

Before diving into the script, let’s briefly touch upon what shell scripting is. Shell scripting is a method to automate tasks in a Unix or Linux environment. It is a powerful tool for executing a series of commands sequentially and is widely used for system administration, file manipulation, program execution, and automation.

The Script: Appending Text to a File

Here’s a step-by-step breakdown of the script:

Script Code:
# Append text to a file
TEXT="Appended Line"
if [ -f "$FILE" ]; then
    echo "$TEXT" >> "$FILE"
    echo "$TEXT" > "$FILE"

Shebang Line (#!/bin/bash): This line specifies that the script should be run using the Bash shell interpreter.

Defining Variables:

FILE: Holds the name of the file (‘append.txt’) to which we want to append the text.

TEXT: Contains the text (“Appended Line”) to be appended.

Conditional Statement (if [ -f "$FILE" ]; then): Checks if the file ‘append.txt’ already exists. The -f flag is used to check the existence of a regular file.

Appending Text:

echo "$TEXT" >> "$FILE": If the file exists, this line appends the text in the TEXT variable to the file.

echo "$TEXT" > "$FILE": If the file does not exist, this line creates the file and writes the text into it. The > operator is used for writing to a file (creating it if it does not exist).

This shell script demonstrates a basic yet essential operation in file manipulation. Whether you’re a system administrator, a developer, or just an enthusiast, understanding how to append text to a file in shell scripting is a valuable skill that can simplify many tasks.

Author: user